De-popper valve



United States Patent Ofi" 7 3,235,237 Patented Feb. 15, 1966 ICC p3,235,237 DE-POPPER VALVE Vincent A. Goetz, Detroit, and Thomas R. Mein,Dearborn, Mich, assignors to Holley Carburetor Company,

Warren, Mich, a corporation of Michigan Continuation of application Ser.No. 119,392, June 26,

1961. This application Feb. 15, 1965, Ser. No. 436,410

2 Claims. (Cl. 261-41) This application is a continuation of US.application Serial No. 119,392, now abandoned, filed on June 26, 1961 inthe names of Vincent A. Goetz and Thomas R. Mein.

This invention relates to fuel systems for internal combustion engines,and more particularly to means for supplying additional fuel undercertain engine operating conditions.

In the past, internal combustion engine fuel systems have usuallyrequired the use of a so-called power valve which was responsive to therelatively low manifold vacuum existing at high engine load when thethrottle valve is open to supply fuel in addition to the normal fuelsupplied through the main fuel system. Also, it was sometimes desirableto have a separate override valve responsive to high manifold vacuum dueto a closed throttle on deceleration to supply additional fuel duringdeceleration so as to prevent backfiring. Although both the power valveand the override valve were desirable, the override valve was very oftenomitted from the fuel supply system because of its added expense.

Override, which usually occurs during down hill deceler-ation, is thecondition where the vehicle drives the engine at a relatively high speedwith the throttle closed so that the intake manifold vacuum is high,usually exceeding a value of about 21of mercury.

Backfiring is principally caused by the formation of a mixture in thecylinders that is too lean to be ignited by the spark, and the passingof this lean mixture into the exhaust pipe and mufller where it isignited by subsequent firing of the engine. The lean mixtures areusually produced by the return of exhaust gases from the manifold to thecylinders when the intake manifold vacuum is high. Backfiring can heeliminated by enriching the mixture during overrun so that it iscombustible in the cylinders after it is leaned out by the exhaustgases.

Accordingly, it is an object of this invention to provide a means ofcontrolling the flow of fuel at various engine vacuums in order to meetspecial engine fuel requirements and to prevent overrun backfiringthrough the exhaust system. 7

It is a furthefobject of this invention to provide a single device whichis relatively simple in construction and inexpensive to manufacture andwhich will operate both as an override valve and a power valve.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings, wherein:

FIGURE 1 is an elevational view in partial cross-section of a carburetorembodying the invention;

FIGURE 2 is an enlarged cross-sectional view illustrating the inventionin greater detail;

FIGURE 3 is a cross-sectional view taken on the plane of line 3-3 ofFIGURE 2 and looking in the direction of the arrows.

With the foregoing general description of the inven- Cir tion in mind,reference is now made to the drawings.

housing 26. The usual idle and transfer fuel systems would, of course,be present, but they are not shown.

The control lever 30 actuates throttle plate 18, and it is held in theclosed throttle position by spring 32. Passage 34 is themain fuel supplyto discharge nozzle 16, and it communicates with passage 36 having themain metering restriction 33 through which fuel from the reservoir 24 ismetered. Passage 36 communicates with a branch passage 37 having arestriction 39 and leading to the novel combination power and overridevalve assembly 23. Passage 40 having a restriction 42 therein connectsfrom assembly 28 to a discharge port 46 disposed downstream of theclosed throttle 13. Conduit 48 leads to the manifold vacuum port 50 onthe engine side of the throttle valve 18. Gasket 52 seals betweenassembly 28 and fuel bowl 26.

In FIGURES 2 and 3, which illustrate on an enlarged scale thecombination power and override valve assembly 28 contemplated by theinvention, main housing 56 is formed to include a recess 58 so as toform a chamber 60 when the diaphragm 62 has the periphery thereofclamped in any suitable manner between the outer edges of housing 56 andcover 64. Housing 56 has formed therein an opening 54 that connects topassage 37 and main fuel supply passages 36 and 34. A passage 66connects between cylinder 68 and chamber 60. Cylinder 68 has one endformed as seat 70 for the main valve 72 which, when open, allowscylinder 68 to be in communication with the :fuel reservoir 24. Passages74 connect cylinder 6% with the fuel conduit 4-0.

Fixed to the center of diaphragm 62 in any suitable manner is one end ofdiaphragm rod 76 which has fixed thereto or formed therewith a pistonvalve 78, which is located in cylinder 68 and which has passages 80formed therethrough so that the chamber 67 communicates with chamber 69.Flange portion 82 of rod 76 has fixed thereto a rubber or other suitablevalve 84 which normally closes the passage 86 formed in main valve 72through which additional fuel fromreservoir 24 may flow.

Rod 76 extends through passage 86 and into recess 88 of valve 72 whichcontains a resilient member, such as spring 99, compressed between thebottom wall of recess 88 and spring retainer 1% secured at the free endof rod 76. The function of spring 90' is to keep valve 84 normallyseated to close passage 86. 1

Main valve 72 may have a flanged portion 102 which provides an abutmentfor one end of the relatively weak resilient member, such as spring 104,having its other end abutting the end 105 of main housing 56 threadedinto the bottom part of fuel bowl 26. The force of spring 104 tends tokeep the valve 72 away from its seat 70 so that fuel may fiow throughthe openings 106, valve 72, chamber 69, passages 80, chamber 67, passage66, chamber 60, opening 54 and into conduits 37, 36 and 34,

Cover 64 has a recess 108 which becomes chamber 110 when it is fixed tothe housing 56 with diaphragm 62 clamped therebetween so that one side112 of diaphragm 62 becomes a wall of chamber 110. Boss 114 of cover 64is formed with a passage 116 which connects the chamber 110 with pipe 48leading to manifold vacuum port 50.

The operation of the invention is such that when the engine is operatingnormally at a manifold vacuum of approximately 8 to 20 inches ofmercury, the elements of the assembly 28 are in the position shown inFIGURE 2. That is, chamber 110 of which the diaphragm 62 forms one wallis partially evacuated, causing rod 76 to move downwardly and positionvalve 78 so that it blocks off the passages 74; at the same time, theforce of spring 90 causes valve 72 to engage seat 70 so as to preventadded fuel from flowing to the main fuel system 34 and nozzle 16.

When the vacuum drops below some predetermined value (for example, 8inches of mercury) as it does when the throttle 18 is opened wide uponan increase in engine load, the force of spring 99 overcomes the forceof the vacuum acting on diaphragm 62 and causes rod 76 to move upwardly.This permits spring 104 to unseat valve 72 and allows fuel to fiowthrough chamber 6?, passages 80, chamber 67, passage 66, chamber 60,opening 54, conduits 36 and 34 and out nozzle 16. The upward movement ofrod 76 does not, however, open passages 74 because of stops 118 limitingthe upward travel of diaphragm 62; that is, passages 74 are still closedby piston valve 78 when the diaphragm travel is stopped.

During the override condition, the engine manifold vacuum acting ondiaphragm 62 reaches a value of approximately 21 to 25 inches ofmercury, which overcomes the force of spring 90 and causes rod 76 tomove downwardly. When rod 76 moves downwardly, valve 73 is engaged withthe rubber seat 120 so as to prevent fuel flow through passages 80.However, passages 74 are opened when valve 78 is seated upon seat 120.The downward movement of rod 76 also causes valve 84 to move downwardlyand open passage 86 so that additional fuel from reservoir 24 may flowthrough chamber 69, passages 74, annular chamber 122, and conduit 40leading to the discharge port 46.

It is apparent that the valve construction disclosed herein is veryinexpensive and that it is constructed so as to perform the samefunctions as previously used separate power and override valves; thatis, when the engine vacuum is relatively low at wide open throttle, thecombination valve assembly of this invention supplies the additionalfuel required by the engine. During normal engine operation atintermediate engine vacuums, the combination valve cuts off all extrafuel, and the engine operates on the normal idle, transfer and main fuelmetering systems. 011 down hill deceleration or overrun, the enginevacuum is abnormally high, and engine backfiring is likely to result dueto a leaned out mixture being supplied to the engine; at this time, thecombination valve again supplies the additional fuel required to enrichthe mixture and prevent backfiring.

It is also apparent that the amounts of extra fuel supplied and thevacuums required to operate the combination valve are dependent upon thespecific design of the various elements thereof. Furthermore, such avalve could be employed to control the air, rather than the fuel,

' first and second chambers, respectively, having said movable member asa common wall, said first housing member having a conduit through whichpressure may be transmitted to said first chamber, said second housingmember including an outlet opening formed therein and anoutwardly-extending element, a passage extending outwardly through thewall of said element, a stem having one end thereof secured to saiddiaphragm and extending with clearance axially through said element, thesurface of said element adjacent said second housing member being formedas a first valve seat, a portion of said stem positioned within saidelement being formed with an annular valve member thereon adapted to attimes engage said first seat and to at times close said passageextending outwardly through said wall of said element, said stem beingformed adjacent said annular valve member to provide a second valvemember, the inner surface of said element being formed at the free endthereof to provide a second valve seat, a separate valve memberpositioned over said stem member with clearance, said separate memberbeing held against said second valve member on said stem by a resilientmeans positioned within said separate member and retained by a shoulderformed on the free end of said stem, and said separate member beingurged away from said second seat by a second resilient means disposedbetween said free end of said element and a shoulder formed on theoutside of said separate member.

2. A pressure responsive valve assembly comprising first and seconddish-shaped housing members secured together with a movable membertherebetween so as to form adjacent first and second chambers,respectively, having said movable member as a common wall, said firsthousing member having a conduit through which pressure may betransmitted to said first chamber, said second housing member having anoutlet opening formed therein and an axially-disposedoutwardly-extending cylindrical portion, the free end of which isexternally threaded, a plurality of passages extending outwardly throughthe wall of said cylindrical portion, a stem having one end thereofsecured to the center of said diaphragm and extending with clearanceaxially through said cylindrical portion, the inner surface of saidcylindrical portion adjacent said second housing member being formed asa first valve seat, a portion of said stem positioned within saidcylindrical portion being formed with an annular valve member thereonadapted to at times engage said first seat and to at times close saidpassages extending outwardly through said wall of said cylindricalportion, said stern being formed adjacent said annular valve member toprovide a second valve member, the inner surface of said cylindricalportion being formed at the free end thereof to provide a second valveseat, a separate hollow valve member positioned over said stem memberwith clearance, said hollow valve member being held against said secondvalve member on said stem by a spring positioned within said hollowvalve member and retained by a shoulder on the free end of said stem,and said hollow .valve member being urged away from said second seat bya spring disposed between said free end of said cylindrical portion anda shoulder formed on the outside of said hollow valve member.

References Cited by the Examiner UNITED STATES PATENTS 2,345,547 3/1944Roth et al. 137-4936 X 2,621,911 12/1952 Lindsteadt. 2,623,535 12/1952Morgan 251 -322 2,631,832 3/1953 Heiger.

FOREIGN PATENTS 855,182 11/1952 Germany.

HARRY B. THORNTON, Primary Examiner.

1. A PRESSURE RESPONSIVE VALVE ASSEMBLY COMPRISING FIRST AND SECONDHOUSING MEMBERS SECURED TOGETHER WITH A MOVABLE MEMBER THEREBETWEEN SOAS TO FORM ADJACENT FIRST AND SECOND CHAMBERS, RESPECTIVELY, HAVING SAIDMOVABLE MEMBER AS A COMMON WALL, SAID FIRST HOUSING MEMBER HAVING ACONDUIT THROUGH WHICH PRESSURE MAY BE TRASMITTED TO SAID FIRST CHAMBER,SAID SECOND HOUSING MEMBER INCLUDING AN OUTLET OPENING FORMED THEREINAND AN OUTWARDLY-EXTENDING ELEMENT, A PASSAGE EXTENDING OUTWARDLYTHROUGH THE WALL OF SAID ELEMENT, A STEM HAVING ONE END THEREOF SECUREDTO SAID DIAPHRAGM AND EXTENDING WITH CLEARANCE AXIALLY THROUGH SAIDELEMENT, THE SURFACE OF SAID ELEMENT ADJACENT SAID SECOND HOUSING MEMBERBEING FORMED AS A FIRST VALVE SEAT, A PORTION OF SAID STEM POSITIONEDWITHIN SAID ELEMENT BEING FORMED WITH AN ANNULAR VALVE MEMBER THEREONADAPTED TO AT TIMES ENGAGE SAID FIRST SEAT AND TO AT TIMES CLOSE SAIDPASSAGE EXTENDING OUTWARDLY THROUGH SAID WALL OF SAID ELEMENT, SAID STEMBEING FORMED ADJACENT SAID ANNULAR VALVE MEMBER TO PROVIDE A SECONDVALVE MEMBER, THE INNER SURFACE OF SAID ELEMENT BEING FORMED AT THE FREEEND THEREOF TO PROVIDE A SECOND VALVE SEAT, A SEPARATE VALVE MEMBERPOSITIONED OVER SAID STEM MEMBER WITH CLEARANCE, SAID SEPARATE MEMBERBEING HELD AGAINST SAID SECOND VALVE MEMBER ON SAID STEM BY A RESILIENTMEANS POSITIONED WITHIN SAID SEPARATE MEMBER AND RETAINED BY A SHOULDERFORMED ON THE FREE END OF SAID STEM, AND SAID SEPARATE MEMBER BEINGURGED AWAY FROM SAID SECOND SEAT BY A SECOND RESILIENT MEANS DISPOSEDBETWEEN SAID FREE END OF SAID ELEMENT AND A SHOULDER FORMED ON THEOUTSIDE OF SAID SEPARATE MEMBER.